As the industries have recently rapidly progressed, electronic devices are miniaturized and hence secondary batteries for use in the devices are strongly demanded to be further increased in the capacity. For meeting such demands, a lithium secondary battery having a high energy density, as compared to a nickel-cadmium battery and a nickel-hydrogen battery, has been developed, and intensively improved repeatedly in the performance to date.
The components constituting the lithium secondary battery are roughly classified mainly into a positive electrode, a negative electrode, a separator, and an electrolytic solution. In these components, as the electrolytic solution, a non-aqueous electrolytic solution is generally used, wherein the non-aqueous electrolytic solution is obtained by dissolving an electrolyte, such as LiPF6, LiBF4, LiClO4, LiCF3SO3, LiAsF6, LiN(CF3SO2)2, or LiCF3(CF2)3SO3, in a non-aqueous solvent, e.g., a cyclic carbonate, such as ethylene carbonate or propylene carbonate; a linear carbonate, such as dimethyl carbonate, diethyl carbonate, or ethylmethyl carbonate; a cyclic ester, such as γ-butyrolactone or γ-valerolactone; or a linear ester, such as methyl acetate or methyl propionate.
In recent years, there are problems to be solved on a global scale, such as environmental problems and energy problems, and lithium secondary batteries are expected to be applied to large-size power sources including a car power source and a stationary power source. However, the batteries applied to such uses are generally presumed to be used in an environment exposed to the air, and therefore, in the development of the batteries, efforts are focused on the battery characteristics in an environment at low temperatures, such as sub-zero temperatures, particularly on the low-temperature resistance characteristics. Further, the batteries are required to have more excellent life performance than conventional lithium secondary batteries due to the uses of the batteries.
As one of attempts to further improve various characteristics of the lithium secondary battery, a method of adding an arbitrary compound to the above-mentioned electrolytic solution has been attempted.
For example, patent documents 1 and 2 have proposed a technique of using a hydroxy acid derivative in a non-aqueous electrolyte when using a carbon material in the negative electrode. Further, patent documents 3 and 4 have proposed a technique of adding a specific sulfonic ester to a non-aqueous electrolyte.